Evidence Brief: Health Effects of Cannabis Exposure in Pregnancy and Breastfeeding

EVIDENCE BRIEF

Health Effects of Cannabis Exposure in Pregnancy

and Breastfeeding

November 2018

Key Messages There is very limited evidence on the impact of cannabis use in preconception, pregnancy and

breastfeeding on neonatal, behavioural and neurocognitive outcomes in early life.

There is inconsistent evidence on the effects of cannabis exposure on health outcomes such as

low birth weight and preterm delivery, depending on the ability to control for tobacco use.

Main limitations of the current evidence include: relatively few studies on humans, poor control

for concurrent exposures including alcohol and tobacco, as well as other potential confounders

and lack of consistent and accurate measures of cannabis exposure.

Guidelines recommend routine screening, providing comprehensive care, counselling on the

risks of substance use and encouraging breastfeeding unless risks outweigh benefits.

Evidence Brief: Health Effects of Cannabis Exposure in Pregnancy and Breastfeeding 2

Background Cannabis is the term used to refer to the cannabis plant, Cannabis sativa, and its products.1 It contains

the compound delta-9-tetrahydrocannabinol (THC), the main psychoactive component which produces a

number of effects, such as euphoria and changes in perception following inhalation or ingestion.2,3

Cannabis is the most frequently used substance worldwide, aside from alcohol and tobacco.4 In the

United States, 24 states and Washington DC have passed legislation permitting medical use of cannabis;

eight of those states have also legalized cannabis for non-medical use.5 Medical use of cannabis has

been legal in Canada since 2001,6 non-medical use of cannabis became legal in fall 2018.

Cannabis Legalization In June 2018, the Government of Canada passed legislation to legalize recreational cannabis as of

October 17, 2018. In its Final Report (submitted November, 2016), the Government’s Task Force on

Cannabis Legalization and Regulation proposed a regulatory framework that aims to limit access and

minimize cannabis-related harms.7 First among its stated objectives is the protection of children and

youth, who may be particularly susceptible to the neurodevelopmental effects of cannabis.

Prevalence of Cannabis Use in Preconception, Pregnancy and

Breastfeeding According to the 2015 Canadian Tobacco, Alcohol and Drugs Survey (CTADS), 13% of Ontario

adolescents and adults reported using cannabis in the past year and 45% reported using it at least once

in their lifetime.8 Young adults (age 20-24 years old) were most likely to report using cannabis, with 30%

reporting that they had used it in the past year. The 2015 prevalence of cannabis use increased among

all females from 7% in 2013 to 10% in 2015.8 As almost half of pregnancies are unplanned9,10 and many

women do not realize they are pregnant until the fifth week of gestation,11 some women who wish to

avoid cannabis use during pregnancy may not be able to do so. The 2009 Canadian Maternity

Experiences Survey showed approximately 7% of women reported non-medical street drug use in the

three months before pregnancy.12

Cannabis is the most frequently used substance in pregnancy, aside from tobacco and alcohol.13,14 The

2009 Canadian Maternity Experiences Survey showed 1% of women reported using cannabis during

pregnancy;12 however, further Canadian data on the use of cannabis in pregnancy is limited. In the

United States, the 2016 National Survey on Drug Use and Health (NSDUH) estimated past month

cannabis use in all pregnant women 15-44 years is approximately 4.9%.15 One study using NSDUH data

showed a 62% increase in cannabis use in pregnant women 18-44 years, from 2.4% in 2002 to 3.9% in

2014.16 Estimates of cannabis use at any time during pregnancy depend upon the population studied.

For example, prevalence can range between 1.0% in the general population to 28% in women who

reported using drugs at least once during the pregnancy.17 Higher rates of cannabis use have been

reported in women who are 18 to 25 years, unmarried or have a lower income.18 Although past-month

cannabis use has been reported to be highest among those in their first trimester (7.4%) and lowest

Evidence Brief: Health Effects of Cannabis Exposure in Pregnancy and Breastfeeding 3

among those in their third trimester (1.8%),18 one study reported substance use rebounds in the three

months postpartum.19

There are minimal data on the prevalence of cannabis use during the lactation period. One recent study

from Colorado, a state with legalized cannabis for medical and non-medical use, estimated 5% of

mothers who reported ever breastfeeding, also reported using cannabis in the postpartum period.20 This

estimate was similar to the reported use any time during pregnancy of 5.7%. Cannabis use in pregnancy

has not been shown to affect likeliness to breastfeed; however, prenatal and postnatal uses of cannabis

were both associated with shorter breastfeeding duration.20

There is concern that legalization of non-medical use will lead to social normalization and low perceived

risk of harms.21 Women have reported using cannabis during pregnancy to alleviate nausea in the first

trimester. One Canadian survey found 77% of medicinal cannabis use during pregnancy was related to

nausea.22 This use may reflect advice provided by sellers. A survey of cannabis retail outlets in Colorado

found 69% recommended cannabis products for “morning sickness” and 36% endorsed the safety of

cannabis products during pregnancy.23

Potential Adverse Outcomes of Cannabis Use in Pregnancy and

Breastfeeding The effects of alcohol and tobacco use during pregnancy are well established. Although less well studied,

there may also be adverse effects from exposure to cannabis in-utero (through maternal use prior to or

during pregnancy) or through breastfeeding.24 As cannabis is now legal, it is important to understand the

effects of exposure to cannabis in pregnancy and through breastfeeding. A study in rats indicates that

THC crosses the placenta.25 While studies in humans were not identified, similar results would be

expected in other mammals. THC is a lipophilic compound that is absorbed into fat tissue and has been

shown to remain in human breast milk for several weeks.26,27 THC functions as an agonist to cannabinoid

receptors, which make up the endocannabinoid system: essential for attention, cognition, memory and

emotion.28 Based on these mechanisms, in utero exposure to cannabis may result in growth restriction

and poor neurodevelopmental outcomes.29 These include growth (birth weight, length, head

circumference), preterm delivery, stillbirth, neonatal behaviours (stimuli habituation, tremors and

startle, nighttime arousal and sleep time) and cognitive outcomes (verbal/memory processing,

attention, impulsivity, cognitive performance).30

Issue and Research Question With the legalization of non-medical cannabis use in Canada, public health providers may get more

questions regarding cannabis use in pregnancy and while breastfeeding. This Evidence Brief addresses

two questions:

1. What are the child and youth outcomes associated with exposure to maternal cannabis use

during preconception, pregnancy or breastfeeding?

Evidence Brief: Health Effects of Cannabis Exposure in Pregnancy and Breastfeeding 4

2. What are the current clinical recommendations for providers caring for reproductive-age,

pregnant or breastfeeding women who may use cannabis?

Methods Public Health Ontario (PHO) Library Services conducted an extensive search from 2006 until April 2018.

Database searches were conducted in Ovid MEDLINE, Embase, PsycINFO and CINAHL. Search terms

related to cannabis, conception, pregnancy, breastfeeding and infancy were used. Searches were limited

to review-level articles published in the English language. Titles and abstracts were independently

screened by two reviewers. Full-text articles meeting inclusion criteria were retrieved and

independently screened by both reviewers. Disagreements at either screening stage were resolved

through consensus. A search of the grey literature was also conducted to identify reviews and clinical

practice guidelines.

Articles were eligible for inclusion if they were: systematic reviews, human studies and reported on the

effects of cannabis exposure on offspring through maternal use during preconception, pregnancy,

infancy or childhood. All health, developmental or social outcomes were included. Guidelines were

included if they used a structured approach to review scientific literature and a transparent method for

generating evidence-based recommendations.

Data extraction for all included articles was conducted by a single reviewer. Quality of included articles

was conducted by two reviewers using The Health Evidence (HE) Quality Assessment Tool31 for

systematic reviews and the AGREE II Guideline Appraisal Tool for clinical practice guidelines.32 The full

search strategy, data extraction tables, PRISMA flow chart and quality appraisal tables, are available

from PHO on request.

Main Findings The search results identified 4,164 articles. After title, abstract screening and full text review, six

systematic reviews,33-38 three with meta-analyses33-35 and five guidelines39-43 met the inclusion criteria

for this brief.

Four systematic reviews were rated as ‘strong,’ two were rated as ‘moderate’ (Table 1).

Table 1: Quality appraisal of articles

Study design Reference Rating

Systematic review and meta-analysis [Gunn 2016] 10/10

Systematic review and meta-analysis [Connors 2016] 9/10

Systematic review and meta-analysis [Ruisch 2018] 9/10

Systematic review [Ordean 2013] 9/10

Evidence Brief: Health Effects of Cannabis Exposure in Pregnancy and Breastfeeding 5

Study design Reference Rating

Systematic review [Seabrook 2017] 6/10

Systematic review [Brown 2018] 5/10

The findings below summarize current evidence from systematic reviews of cannabis exposure during

pregnancy and lactation, followed by a description of current clinical practice guidelines. There was no

review-level evidence identified that examined cannabis exposure explicitly during the preconception

period.

Exposure to Cannabis during Pregnancy Three strong systematic reviews with meta-analyses examined child and youth health outcomes

associated with cannabis use during pregnancy.33-35

The first systematic review by Conner et al. (2016) identified 31 primary studies examining cannabis use

during pregnancy on multiple neonatal outcomes including low birth weight, preterm delivery, birth

weight, gestational age at delivery, level II or greater nursery admission, stillbirth, spontaneous abortion,

Apgar score, placental abruption and perinatal death. The majority of studies used maternal self-report

to measure cannabis exposure. The pooled unadjusted estimates showed infants born to women who

used cannabis were at increased risk for low birth weight (RR: 1.43, 95% CI 1.27-1.62) and preterm

delivery (RR: 1.32, 95% CI 1.14-1.54).33 In this study, multiple meta-analyses were conducted to assess

the independent risk of cannabis separately from tobacco use and other substances, as well as

socioeconomic and demographic factors. Despite unadjusted estimates showing increased risk for

multiple outcomes, the pooled adjusted estimates were not statistically significant. The meta-analysis

was limited by small sample sizes of the included studies and was likely underpowered to detect

significant differences. Authors concluded that when confounding factors were controlled for, cannabis

use did not have an effect on adverse neonatal outcomes.33

The second systematic review and meta-analysis by Gunn et al. (2016) identified 24 primary studies. The

main outcomes that were examined included maternal anaemia, birth weight, neonatal length,

placement in the neonatal intensive care unit (NICU), gestational age, head circumference and preterm

birth. The review conceded the main limitation of the primary studies identified was the inability to

separate cannabis use from poly-substance use because in most of the studies these data were

unavailable. As such, the meta-analysis was unable to control for these important factors. Results

showed, based on pooled data, pregnant women who used cannabis during pregnancy had a 1.36 (95%

CI 1.10-1.69) higher odds of anaemia compared to those who did not use cannabis. There was a

significant reduction in birth weight of 109.42 g (95% CI 38.72-180.12) and higher odds of low birth

weight (<2500 g) (pooled OR (pOR): 1.77, 95% CI 1.07-3.01).34 NICU admission was also significantly

increased for infants with cannabis exposure in pregnancy compared to those not exposed (pOR: 2.02,

95% CI 1.27-3.21). The authors concluded that cannabis use during pregnancy was associated with poor

Evidence Brief: Health Effects of Cannabis Exposure in Pregnancy and Breastfeeding 6

outcomes for both women and their children; however, they could not control for the use of other

substances such as alcohol and tobacco.34

Finally, Ruisch et al. (2018) examined substance use (caffeine, alcohol, tobacco and cannabis) during

pregnancy and the association with conduct problems in children. In this review, only three studies were

identified that examined cannabis use.35 The age of assessment for conduct problems was between 5

and 18 years. Results from the pooled data did not indicate a significant association between cannabis

use in pregnancy and conduct problems in children or youth (pOR: 1.29, 95% CI 0.93-1.81); however, the

quality assessment of the three included studies was ‘low to very low’ and the authors determined there

were insufficient studies to draw conclusions for this association.35

Exposure to Cannabis during Lactation Three systematic reviews were identified that examined the association between cannabis use during

breastfeeding and infant outcomes.36-38 One review identified three studies in humans and three in

animals.37 The other review included the same three human studies and identified an additional

prospective cohort study.36 The third review included the two previous systematic reviews and one

additional primary study.38 The primary studies included in all three reviews were limited in number,

dated and had overlap between reviews.

Across systematic reviews, cannabis use during breastfeeding was not found to be associated with any

health outcomes in humans or animals. Infant health outcomes examined included mental and motor

development at one year of age, physical growth and sudden infant death syndrome (SIDS). Overall,

there were very few studies and the quality was rated as ‘moderate’ to ‘very low.’36 A main limitation of

the studies included in the systematic reviews is the failure to adjust for maternal cannabis use in the

first trimester of pregnancy.44 The conclusions from one review emphasizes informed decision making

where pregnant women need to be counselled on the potential risks of cannabis use and benefits of

breastfeeding, before deciding on infant feeding practices.36 While the authors of the other two reviews

interpreted the evidence with a precautionary perspective and concluded women who are

breastfeeding should be advised to reduce or abstain from cannabis use.37,38

Clinical Guidelines Each guideline identified was quality appraised by two reviewers. Two guidelines were rigorously

developed, had multiple stakeholder involvement and clear recommendations.39,41 Three guidelines

were limited by incomplete search strategies, lack of criteria for selecting evidence and less stakeholder

involvement.40,42,43 One guideline was excluded due to poor quality; specifically the lack of a systematic

strategy for identifying evidence.45

Guidelines from the Society for Obstetrics and Gynecologists of Canada (SOGC) and the World Health

Organization (WHO) were identified that provided recommendations to screen, treat and manage

substance use in women who are pregnant and breastfeeding. The American College of Obstetrics and

Gynecologists (ACOG) and the American Academy of Pediatrics (AAP) released guidelines that focused

specifically on the use of cannabis and cannabinoid-containing products in pregnancy and breastfeeding.

Evidence Brief: Health Effects of Cannabis Exposure in Pregnancy and Breastfeeding 7

One additional guideline was included that focused on cannabis use in breastfeeding from the Academy

of Breastfeeding Medicine (ABM). Recommendations for health care providers on cannabis use during

pregnancy and breastfeeding are presented in Table 2.

There are consistent recommendations for health care providers to counsel women to abstain or reduce

cannabis use while pregnant. In addition, the AAP recommends counseling young women in the

preconception period about the lack of evidence and potential risks of cannabis exposure on infant and

child development.42 For breastfeeding, there is consensus among professional societies for health care

providers to counsel breastfeeding mothers on the potential risks of cannabis use during lactation and

support efforts to abstain from use. For mothers with substance use disorders, the WHO recommends

that breastfeeding should be encouraged “unless the risks clearly outweigh the benefits.”41 The strength

of this recommendation was reported “conditional” because of the likely dose response of substance

use; individuals with heavy or chronic use may accumulate higher concentrations of THC in the breast

milk and therefore pose higher risks to exposed infants.41 These recommendations were based on low

quality evidence.

Table 2: Recommendations and guidelines from other organizations

Organization Recommendation

During pregnancy

Society of Obstetricians and

Gynaecologists of Canada (SOGC)

“Health care providers should advise pregnant women to abstain from

or reduce cannabis use during pregnancy to prevent negative long-term

cognitive and behavioural outcomes for exposed children (II-1A)”39

p.932

World Health Organization (WHO) “Health-care providers should, at the earliest opportunity, advise

pregnant women dependent on alcohol or drugs to cease their alcohol

or drug use and offer, or refer to, detoxification services under medical

supervision where necessary and applicable.”41

American College of Obstetricians and

Gynaecologists (ACOG)

“Women who are pregnant or contemplating pregnancy should be

encouraged to discontinue marijuana use”43

p.3

American Academy of Pediatrics (AAP) “Women who are considering becoming pregnant or who are of

reproductive age need to be informed about the lack of definitive

research and counseled about the current concerns regarding potential

adverse effects of THC use on the woman and on fetal, infant, and child

development. Marijuana can be included as part of a discussion about

the use of tobacco, alcohol, and other drugs and medications during

pregnancy.”42

p.10-11

“As part of routine anticipatory guidance and in addition to

contraception counseling, it is important to advise all adolescents and

young women that if they become pregnant, marijuana should not be

used during pregnancy.”42

p.11

Evidence Brief: Health Effects of Cannabis Exposure in Pregnancy and Breastfeeding 8

Organization Recommendation

During breastfeeding

Society of Obstetricians and

Gynaecologists of Canada (SOGC)

“Women with active substance use should be encouraged to

discontinue alcohol or other drug use while breastfeeding, and the risks

and benefits of breastfeeding versus breast milk exposure to

substances should be discussed (II-2B)”39

p.933-4

World Health Organization (WHO) “A. Mothers with substance use disorders should be encouraged to

breastfeed unless the risks clearly outweigh the benefits.

B. Breastfeeding women using alcohol or drugs should be advised and

supported to cease alcohol or drug use; however, substance use is not

necessarily a contraindication to breastfeeding. SOR: Conditional;

Quality of Evidence: Low”41

p.15

American College of Obstetricians and

Gynaecologists (ACOG)

“Breastfeeding women should be informed that the potential risks of

exposure to marijuana metabolites are unknown and should be

encouraged to discontinue marijuana use.”43

p.3

American Academy of Pediatrics (AAP) “Present data are insufficient to assess the effects of exposure of

infants to maternal marijuana use during breastfeeding. As a result,

maternal marijuana use while breastfeeding is discouraged. Because

the potential risks of infant exposure to marijuana metabolites are

unknown, women should be informed of the potential risk of exposure

during lactation and encouraged to abstain from using any marijuana

products while breastfeeding.”42

p.11

The Academy of Breastfeeding Medicine

(ABM)

“A recommendation of abstaining from any marijuana use is

warranted. At this time, although the data are not strong enough to

recommend not breastfeeding with any marijuana use, we urge

caution.”40

p.139

*Bold emphasis added

Discussion There are three main limitations of the current evidence on the effects of cannabis use in pregnancy and

breastfeeding: 1) relatively few studies on humans, 2) poor control for concurrent exposures including

alcohol and tobacco, as well as other potential confounders and 3) lack of consistent and accurate

measures of cannabis exposure.

Lack of Human Epidemiologic Studies The primary studies that were included in the three systematic reviews were predominantly from three

longitudinal cohort studies: the Ottawa Prenatal Prospective Study (OPPS) in Ottawa, Maternal Health

Practices and Child Development Project (MHPCD) in Pittsburgh and the Generation R study in

Rotterdam, the Netherlands. The OPPS and MHPCD were initiated in the 1980s and have followed

children into adulthood. However, potency of cannabis consumed has changed substantially; average

THC concentration increased from 4% in 1995 to 12% in 2014.46 As such, results from studies based on

Evidence Brief: Health Effects of Cannabis Exposure in Pregnancy and Breastfeeding 9

past use may not be applicable to current use. These cohorts also had relatively small sample sizes,

specific populations and looked at different outcomes, which increases the heterogeneity of studies

included in meta-analyses. Therefore to understand the current effects of cannabis use, new high quality

observational studies are required.

Poor Control of Concurrent Exposures and Other Confounders Poly-substance use with cannabis is common. In one study, 5.5% of all women reported simultaneous

alcohol and cannabis use.47 Children exposed to alcohol, tobacco and other illicit drugs have known

negative health outcomes. Therefore, if studies are unable to control for poly-substance use it will limit

our understanding of the independent effects of cannabis. Similarly, exposure to other chemicals in the

community and work environment, which have been associated with outcomes of interest, was not well

addressed in most studies. Conner et al., (2016) and Gunn et al., (2016) included 31 and 24 studies,

respectively; however, only eight studies were reported in both systematic reviews and only one study

was used in both meta-analyses of low birth weight.33,34 The conclusions of these two reviews were

conflicting; Conner reported no independent risk of cannabis on any neonatal outcomes while Gunn

reported overall adverse effects of cannabis use during pregnancy. The difference between these two

meta-analyses was the ability to control for poly-substance use, especially tobacco. Conner et al.,

included only four studies that had reported tobacco use and could be adjusted for. Gunn et al.,

acknowledged the inability to control for tobacco use as a limitation of their study and had a total of 12

studies included in the meta-analyses.

Measurement of Cannabis Exposure One main limitation of studies on cannabis exposure in the pregnancy and breastfeeding period is the

measurement of exposure. Self-reporting cannabis use is the most common method of ascertaining

exposure; however, similar to alcohol, there are strong social desirability and reporting biases that

would likely underestimate use and therefore underestimate effects.16 Further, the previous illicit drug

status of cannabis may impede mothers or any caregivers from accurately reporting use due to concerns

of involvement with child protective services. There are methods of measuring cannabis exposure using

biological samples including maternal serum, urine or hair, which can detect cannabis from two to three

days to several weeks post exposure depending on frequency of use. To measure exposure in the infant,

researchers have used meconium, the first stool of a newborn, which can detect past exposure to

marijuana in the second or third trimester or neonatal hair, which can detect exposure in the third

trimester. Unfortunately, these biological sampling procedures are expensive, often impractical in many

sites and produce high false positive rates.48 More research is required to develop reliable and accurate

metrics for cannabis exposure.

Limitations This evidence brief is not without limitations. Our review did not include search terms for the effect of

cannabis use on parenting, parent-child attachment or any related outcomes, which may have an effect

on later child health outcomes. Although there is evidence on second-hand smoke from tobacco

research, the independent association of second-hand smoke from parental cannabis use and early

Evidence Brief: Health Effects of Cannabis Exposure in Pregnancy and Breastfeeding 10

childhood outcomes is unknown. Future research should investigate this association. We focused on

literature published since 2006, emphasized the use of systematic reviews rather than primary studies and

did not include primary studies or systematic reviews only reported in the grey literature. Large well-

conducted cohort studies would be most useful for studying the extent of cannabis-related harms. Ideally,

such studies would examine cannabis exposures at various dosages, routes (i.e., in utero, lactation) and

points in the early life course and control for important confounders.

Conclusion There is limited and inconsistent evidence on the effects of cannabis exposure during pregnancy and

breastfeeding on infant, child and youth health outcomes. Although evidence is limited, clinical

guidelines for cannabis use during pregnancy provide consistent recommendations for pregnant women

to abstain, although one guideline recommended women to abstain or reduce use. Similarly, in light of

the established benefits of breastfeeding, guidelines recommend women should be encouraged to

discontinue cannabis use while breastfeeding. In addition, many guidelines recommend informing

women who are breastfeeding and using cannabis of potential risks of exposure including considerations

of the frequency and amount of cannabis use. In this way, recommendations about breastfeeding for

women using cannabis can be individualized during discussion with a health care provider. For

additional information, the Canadian Centre for Substance Abuse (CCSA) also released an updated

overview of current evidence on cannabis use during pregnancy.1 Although the review does not provide

recommendations, the author’s conclusions align with those of this review.

Implications for Practice Ontario’s local public health agencies have a mandate to support healthy child growth and development

and are responsible for providing relevant health advice to the public, health care providers and policy-

makers.49 For example, in collaboration with the Ministry of Children, Community and Social Services,

local public health nurses deliver the Healthy Babies Healthy Children50 program and provide evidence-

based guidance on child health to new and expectant parents. Given the recent legalization of non-

medical cannabis use in Canada, it will be increasingly important for public health staff to be equipped

to address this topic with their clients.

The evidence included in this brief does not confirm or convincingly rule out that early cannabis

exposure adversely impacts early childhood outcomes, but suggests possible risks.29 Given the potential

for health, social and developmental harms, a precautionary approach may be warranted. Therefore,

abstinence during pregnancy and lactation is the safest approach and reduces risk of potential harms.

Public health staff may caution against maternal cannabis use during preconception, pregnancy and

lactation periods and provide support for the health and social needs that may contribute to cannabis

use; however, evidence on the effectiveness of this approach or on other specific interventions is

lacking.

Evidence Brief: Health Effects of Cannabis Exposure in Pregnancy and Breastfeeding 11

Additional surveillance of cannabis use and cannabis-related harms would also support evidence-

informed decision making. The federal Task Force has recommended that the federal and provincial

governments collect and share data regarding health, social and other outcomes following cannabis

legalization.7 Such data could be used to improve the quality of health advice provided by public health

officials.

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Specifications and Limitations of Evidence Brief The purpose of this Evidence Brief is to investigate a research question in a timely manner to help

inform decision making. The Evidence Brief presents key findings, based on a systematic search of the

best available evidence near the time of publication, as well as systematic screening and extraction of

the data from that evidence. It does not report the same level of detail as a full systematic review. Every

attempt has been made to incorporate the highest level of evidence on the topic. There may be relevant

individual studies that are not included; however, it is important to consider at the time of use of this

brief whether individual studies would alter the conclusions drawn from the document.

Authors Dr. Sarah Carsley, Applied Public Health Science Specialist, Health Promotion, Chronic Disease and Injury

Prevention

Dr. Pamela Leece, Public Health Physician, Health Promotion, Chronic Disease and Injury Prevention

Contributors Harkirat Singh, Research Coordinator, Health Promotion, Chronic Disease and Injury Prevention

Chase Simms, Research Assistant, Health Promotion, Chronic Disease and Injury Prevention

Erin Berenbaum, Research Coordinator, Health Promotion, Chronic Disease and Injury Prevention

Sue Keller-Olaman, Manager, Health Promotion, Chronic Disease and Injury Prevention

Susan Massarella, Library Information Specialist, Library Services

Beata Pach, Manager, Library Services

Evidence Brief: Health Effects of Cannabis Exposure in Pregnancy and Breastfeeding 16

Reviewers Dr. Heather Manson, Chief, Health Promotion, Chronic Disease and Injury Prevention

Dr. Brent Moloughney, Medical Director, Health Promotion, Chronic Disease and Injury Prevention

Dr. Ray Copes, Chief, Environmental and Occupational Health

External Reviewer Dr. Alice Ordean, Department of Family Medicine, St. Joseph's Health Centre, Toronto

Citation Ontario Agency for Health Protection and Promotion (Public Health Ontario), Carsley S, Leece P.

Evidence brief: Health effects of cannabis exposure in pregnancy and breastfeeding. Toronto, ON:

Queen’s Printer for Ontario; 2018.

ISBN 978-1-4868-2712-1

©Queen’s Printer for Ontario, 2018

Disclaimer This document was developed by Public Health Ontario (PHO). PHO provides scientific and technical

advice to Ontario’s government, public health organizations and health care providers. PHO’s work is

guided by the current best available evidence at the time of publication.

The application and use of this document is the responsibility of the user. PHO assumes no liability

resulting from any such application or use.

This document may be reproduced without permission for non-commercial purposes only and provided

that appropriate credit is given to PHO. No changes and/or modifications may be made to this document

without express written permission from PHO.

For Further Information Health Promotion, Chronic Disease and Injury Prevention

Email: hpcdip@oahpp.ca

Evidence Brief: Health Effects of Cannabis Exposure in Pregnancy and Breastfeeding 17

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